The study will evaluate the efficacy and safety of an investigational drug called SAM-531 at three dosage levels. Subjects will receive either one of the 3 dosage levels of SAM-531, donepezil or placebo for the first 24 weeks of the study (period I). Subjects who receive placebo for period I will be assigned to receive the highest dose of SAM-531 SAM-531 for the remaining 28 weeks of the study, while subjects who received one of the three SAM-531 dosage levels or donepezil in period I will continue with the same study drug (period II).
The study was stopped (date of termination was 13April2011) due to a 6 month interim analysis: all of the 3 SAM-531 dosage levels were declared futile. There were no safety concerns.
Capsules SAM-531 placebo and 5 mg tablet encapsulated Donepezil placebo capsules, once a day during 24 weeks.
Capsules SAM-531 1.5 mg, once a day during 52 weeks.
Capsules SAM-531 3.0 mg, once a day during 52 weeks.
Capsules SAM-531 5.0 mg, once a day during 24 weeks or 52 weeks.
Encapsulated Donepezil 5 mg tablets, once a day during 52 weeks. After Day 42, the dose can up titrated up to 10 mg of Donepezil.
C.a.b.a., Buenos Aires, Argentina
Caba, Buenos Aires, Argentina
Ciudad de Buenos Aires, Argentina
Ciudad de Buenos Aires, Argentina